IBM Hardware Interrupts Used on the CMX58886CX cpuModule, Interrupt Normal Use Timer

Hardware Interrupts

Note If you add any expansion modules or other peripherals to the system, you must ensure they do not use interrupts needed by the cpuModule, or malfunctions will occur.

The CMX58886CX cpuModule supports the standard PC interrupts listed in Table 38. Interrupts not in use by hardware on the cpuModule itself are listed as available. Similarly, if the operating system is using APIC, more IRQs will be available.

Table 38 Hardware Interrupts Used on the CMX58886CX cpuModule

Interrupt	Normal Use
0	Timer 0

1Keyboard

2Cascade of IRQ 8–15

3COM2

4COM1

5Available

61Floppy

7Printer

8Real Time Clock

9Available, routed to IRQ 2

10Available

11Available

12Bus Mouse

142 Primary IDE hard disk3

15ATA/IDE Disk Chip socket

1.Floppy disk interrupt, INT6, is available for use if no floppy disk is present in the system and floppy disk is disabled in Setup.

2.Hard disk interrupt, INT14, is available for use if no hard disk drive is present in the system and hard disk is disabled in Setup.

3.IRQs 14 and 15 may be available if the IDE controller is configured in Native Mode (refer to IDE Controller Configuration—page 61)

Note The cpuModule has onboard PCI devices that will claim IRQ lines. In some instances, a PCI device will claim an IRQ line that is required by a legacy device. To reserve an IRQ for a legacy device, refer to the PnP/PCI Configuration Setup fields in the BIOS.

For external devices that require Legacy/ISA interrupts, a serial interrupt signal is available which permits access to the CPU’s hardware interrupts. One pair of Legacy/ISA DMA request/grant signals are also available. For more information on the serial interrupt signal, and the DMA request/grand pair, refer to Bridge Link (CN4) in Chapter 3, Connecting the cpuModule

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